The first aim of the present study is to identify occupations which have the highest prevalence for drug abuse, alcohol dependence, and psychopathology in 100 common occupations. A second aim is to identify objectively-defined characteristics of occupations associated with drug abuse and psychopathology. Application of these separate analytic strategies within the same samples will permit the first epidemiologic characterization of occupational risks associated with these disorders. The research will focus on measures of abuse of marijuana, abuse of alcohol, and four specific areas of psychopathology (anxiety; depression; somatic complaints; and cognitive impairment). Four diagnostic groups (DIS/DSM-III Anxiety disorders; DIS/DSM-III Affective Disorders; DIS/DSM-III Drug Abuse or Dependence; DIS/DSM-III Alcohol Abuse or Dependence) are to be studied also. Data on the current or most recent full-time occupation of the respondent are available, obtained from questions on occupation drawn from the Current Population Survey and coded according to the Census detailed occupational classification. The data set includes 20,860 residents from five diverse areas in the United States, sampled probabilistically in the NIMH Epidemiologic Catchment Area Program. A second data set is the Hispanic HANES, where identical measures on depression and similar measures for marijuana and alcohol abuse, were obtained for a sample of about 12,000. The large community samples, broad range of occupations, and breadth of measurement of drug abuse and psychopathology are not available in prior studies of occupations. The detailed classification of occupation will be used to link these data to three separate systems of classifying occupations according to dimensions proposed to be related to risk for specific types of drug abuse and psychopathology: the dimensions of the Dictionary of Occupational Titles; dimensions originating from work by Karasek and colleagues; and dimensions derived from work by Hoar on chemical exposures. These data sets are publicly available in magnetic form and linkage is straightforward. Two approaches to analysis are proposed. In the first approach the prevalence of specific types of drug abuse and psychopathology will be assessed in specific occupations, searching for what we term "occupational hotspots." In the second type of analysis the DOT, Karasek, and Hoar dimensions will be used as independent variables, yielding what we term "suspect dimensions." Each approach to analysis has particular advantages and disadvantages. Results from these analyses will guide public health practitioners to occupations where prevalence is greatest, and suggest hypotheses whereby occupational environments might cause drug abuse and psychopathology. These results will provide critically important background data for current and future research on drug abuse and psychopathology in specific occupations.